import 'package:flutter/widgets.dart';
import 'package:mobile_scanner/mobile_scanner.dart';
import 'package:seshat/data/repositories/bal_repository.dart';
import 'package:seshat/domain/models/bal.dart';
import 'package:seshat/domain/models/book_instance.dart';
import 'package:seshat/utils/command.dart';
import 'package:seshat/utils/result.dart';

class SellViewModel extends ChangeNotifier {
  SellViewModel({required BalRepository balRepository})
    : _balRepository = balRepository {
    load = Command0(_load)..execute();
  }

  final BalRepository _balRepository;

  bool _showScan = false;
  bool get showScan => _showScan;
  set showScan(bool newValue) {
    _showScan = newValue;
    notifyListeners();
  }

  /*
 * ===============================
 * =====[ BOOKS & INSTANCES ]=====
 * ===============================
*/

  final List<BookInstance> _scannedBooks = [];
  List<BookInstance> get scannedBooks => _scannedBooks;
  void scanBook(BarcodeCapture barcode) {
    final addedBook = BookInstance(
      balId: 5,
      bookId: 5,
      id: _scannedBooks.length,
      ownerId: 5,
      price: 5,
      available: true,
    );
    _scannedBooks.add(addedBook);
    notifyListeners();
  }

  void sendSell() {
    _scannedBooks.clear();
    notifyListeners();
  }

  void deleteBook(int id) {
    _scannedBooks.removeWhere((book) => book.id == id);
    notifyListeners();
  }

  Future<void> scanBook(BarcodeCapture barcode) async {
    int ean = int.parse(barcode.barcodes.first.rawValue!);
    Bal? bal = await _balRepository.ongoingBal();
    _scannedBooks.clear();

    final result = await _bookInstanceRepository.getByEan(bal!.id, ean);
    switch (result) {
      case Ok():
        for (BookInstance instance in result.value) {
          Book book;
          final result2 = await _bookRepository.getBookById(instance.bookId);
          switch (result2) {
            case Ok():
              book = result2.value;
              break;
            case Error():
              continue;
          }
          Owner owner;
          final result3 = await _ownerRepository.getOwnerById(instance.ownerId);
          switch (result3) {
            case Ok():
              owner = result3.value;
              break;
            case Error():
              continue;
          }
          _scannedBooks.add(
            BookStack(instance: instance, book: book, owner: owner),
          );
        }
        break;
      case Error():
        break;
    }

    isScanLoaded = true;
    notifyListeners();
    return;
  }

  /*
 * =================
 * =====[ BAL ]=====
 * =================
*/

  Bal? _currentBal;
  get currentBal => _currentBal;

  /*
 * =================================
 * =====[ COMMAND AND LOADING ]=====
 * =================================
*/

  late final Command0 load;
  bool isLoaded = false;

  Future<Result<void>> _load() async {
    final result1 = await _loadBal();
    switch (result1) {
      case Ok():
        isLoaded = true;
        break;
      default:
        break;
    }
    notifyListeners();
    return result1;
  }

  Future<Result<void>> _loadBal() async {
    final result = await _balRepository.getBals();
    switch (result) {
      case Ok():
        _currentBal = result.value
            .where((bal) => bal.state == BalState.ongoing)
            .firstOrNull;
        break;
      case Error():
        break;
    }

    return result;
  }
}